diff --git a/packages/core/src/api/clipboard/fromClipboard/handleFileInsertion.ts b/packages/core/src/api/clipboard/fromClipboard/handleFileInsertion.ts
index 38c9921f18..aa422bb23a 100644
--- a/packages/core/src/api/clipboard/fromClipboard/handleFileInsertion.ts
+++ b/packages/core/src/api/clipboard/fromClipboard/handleFileInsertion.ts
@@ -170,9 +170,14 @@ export async function handleFileInsertion<
 
           const blockRect = blockElement?.getBoundingClientRect();
 
+          const existingBlock = editor.getBlock(id);
+          if (!existingBlock) {
+            return;
+          }
+
           return insertOrUpdateBlock(
             editor,
-            editor.getBlock(id)!,
+            existingBlock,
             fileBlock,
             blockRect && (blockRect.top + blockRect.bottom) / 2 > coords.top
               ? "before"
@@ -183,6 +188,10 @@ export async function handleFileInsertion<
         return;
       }
 
+      if (!insertedBlockId) {
+        return;
+      }
+
       const updateData = await editor.uploadFile(file, insertedBlockId);
 
       const updatedFileBlock =
diff --git a/packages/core/src/blocks/ToggleWrapper/createToggleWrapper.ts b/packages/core/src/blocks/ToggleWrapper/createToggleWrapper.ts
index de2ba427c1..257fd7ce6f 100644
--- a/packages/core/src/blocks/ToggleWrapper/createToggleWrapper.ts
+++ b/packages/core/src/blocks/ToggleWrapper/createToggleWrapper.ts
@@ -50,20 +50,25 @@ export const createToggleWrapper = (
   const toggleButtonOnClick = () => {
     // Toggles visibility of child blocks. Also adds/removes the "add block"
     // button if there are no child blocks.
+    const currentBlock = editor.getBlock(block);
+    if (!currentBlock) {
+      return;
+    }
+
     if (toggleWrapper.getAttribute("data-show-children") === "true") {
       toggleWrapper.setAttribute("data-show-children", "false");
-      toggledState.set(editor.getBlock(block)!, false);
+      toggledState.set(currentBlock, false);
 
       if (dom.contains(toggleAddBlockButton)) {
         dom.removeChild(toggleAddBlockButton);
       }
     } else {
       toggleWrapper.setAttribute("data-show-children", "true");
-      toggledState.set(editor.getBlock(block)!, true);
+      toggledState.set(currentBlock, true);
 
       if (
         editor.isEditable &&
-        editor.getBlock(block)?.children.length === 0 &&
+        currentBlock.children.length === 0 &&
         !dom.contains(toggleAddBlockButton)
       ) {
         dom.appendChild(toggleAddBlockButton);
@@ -111,7 +116,10 @@ export const createToggleWrapper = (
       // If a child block is added while children are hidden, show children.
       if (toggleWrapper.getAttribute("data-show-children") === "false") {
         toggleWrapper.setAttribute("data-show-children", "true");
-        toggledState.set(editor.getBlock(block)!, true);
+        const currentBlock = editor.getBlock(block);
+        if (currentBlock) {
+          toggledState.set(currentBlock, true);
+        }
       }
 
       // Remove the "add block" button as we want to show child blocks and
@@ -124,7 +132,10 @@ export const createToggleWrapper = (
       // children.
       if (toggleWrapper.getAttribute("data-show-children") === "true") {
         toggleWrapper.setAttribute("data-show-children", "false");
-        toggledState.set(editor.getBlock(block)!, false);
+        const currentBlock = editor.getBlock(block);
+        if (currentBlock) {
+          toggledState.set(currentBlock, false);
+        }
       }
 
       // Remove the "add block" button as we want to hide child blocks,
diff --git a/packages/core/src/extensions/SideMenu/SideMenu.ts b/packages/core/src/extensions/SideMenu/SideMenu.ts
index e5572c004c..d53a8444cc 100644
--- a/packages/core/src/extensions/SideMenu/SideMenu.ts
+++ b/packages/core/src/extensions/SideMenu/SideMenu.ts
@@ -241,6 +241,17 @@ export class SideMenuView<
     if (this.editor.isEditable) {
       const blockContentBoundingBox = block.node.getBoundingClientRect();
       const column = block.node.closest("[data-node-type=column]");
+      const sideMenuBlock = this.editor.getBlock(
+        this.hoveredBlock!.getAttribute("data-id")!,
+      );
+      if (!sideMenuBlock) {
+        if (this.state?.show) {
+          this.state.show = false;
+          this.hoveredBlock = undefined;
+          this.emitUpdate(this.state);
+        }
+        return;
+      }
       this.state = {
         show: true,
         referencePos: new DOMRect(
@@ -257,9 +268,7 @@ export class SideMenuView<
           blockContentBoundingBox.width,
           blockContentBoundingBox.height,
         ),
-        block: this.editor.getBlock(
-          this.hoveredBlock!.getAttribute("data-id")!,
-        )!,
+        block: sideMenuBlock,
       };
       this.updateState(this.state);
     }
diff --git a/packages/core/src/extensions/TableHandles/TableHandles.ts b/packages/core/src/extensions/TableHandles/TableHandles.ts
index 4616d76b70..4a019aa3db 100644
--- a/packages/core/src/extensions/TableHandles/TableHandles.ts
+++ b/packages/core/src/extensions/TableHandles/TableHandles.ts
@@ -533,10 +533,10 @@ export class TableHandlesView implements PluginView {
     }
 
     // Hide handles if the table block has been removed.
-    this.state.block = this.editor.getBlock(this.state.block.id)!;
+    const refreshedBlock = this.editor.getBlock(this.state.block.id);
     if (
-      !this.state.block ||
-      this.state.block.type !== "table" ||
+      !refreshedBlock ||
+      refreshedBlock.type !== "table" ||
       // when collaborating, the table element might be replaced and out of date
       // because yjs replaces the element when for example you change the color via the side menu
       !this.tableElement?.isConnected
@@ -548,6 +548,7 @@ export class TableHandlesView implements PluginView {
 
       return;
     }
+    this.state.block = refreshedBlock as typeof this.state.block;
 
     const { height: rowCount, width: colCount } = getDimensionsOfTable(
       this.state.block,
diff --git a/packages/react/src/blocks/ToggleWrapper/ToggleWrapper.tsx b/packages/react/src/blocks/ToggleWrapper/ToggleWrapper.tsx
index 7fa0a4bc9a..b35fc8d779 100644
--- a/packages/react/src/blocks/ToggleWrapper/ToggleWrapper.tsx
+++ b/packages/react/src/blocks/ToggleWrapper/ToggleWrapper.tsx
@@ -58,10 +58,11 @@ export const ToggleWrapper = (
   );
 
   const handleToggle = (block: Block<any, any, any>) => {
-    (toggledState || defaultToggledState).set(
-      editor.getBlock(block)!,
-      !showChildren,
-    );
+    const currentBlock = editor.getBlock(block);
+    if (!currentBlock) {
+      return;
+    }
+    (toggledState || defaultToggledState).set(currentBlock, !showChildren);
     dispatch({
       type: "toggled",
     });
@@ -91,7 +92,10 @@ export const ToggleWrapper = (
         return 0;
       }
 
-      const newBlock = editor.getBlock(block)!;
+      const newBlock = editor.getBlock(block);
+      if (!newBlock) {
+        return 0;
+      }
       const newChildCount = newBlock.children.length || 0;
 
       if (newChildCount > childCount) {
@@ -122,7 +126,7 @@ export const ToggleWrapper = (
           className="bn-toggle-button"
           type="button"
           onMouseDown={(event) => event.preventDefault()}
-          onClick={() => handleToggle(editor.getBlock(block)!)}
+          onClick={() => handleToggle(block)}
         >
           <svg
             xmlns="http://www.w3.org/2000/svg"
diff --git a/packages/react/src/components/FilePanel/DefaultTabs/EmbedTab.tsx b/packages/react/src/components/FilePanel/DefaultTabs/EmbedTab.tsx
index fd9ab688bf..9c824ba8bf 100644
--- a/packages/react/src/components/FilePanel/DefaultTabs/EmbedTab.tsx
+++ b/packages/react/src/components/FilePanel/DefaultTabs/EmbedTab.tsx
@@ -26,7 +26,7 @@ export const EmbedTab = <
 
   const editor = useBlockNoteEditor<B, I, S>();
 
-  const block = editor.getBlock(props.blockId)!;
+  const block = editor.getBlock(props.blockId);
 
   const [currentURL, setCurrentURL] = useState<string>("");
 
@@ -41,7 +41,10 @@ export const EmbedTab = <
     (event: KeyboardEvent) => {
       if (event.key === "Enter" && !event.nativeEvent.isComposing) {
         event.preventDefault();
-        editor.updateBlock(block.id, {
+        if (!editor.getBlock(props.blockId)) {
+          return;
+        }
+        editor.updateBlock(props.blockId, {
           props: {
             name: filenameFromURL(currentURL),
             url: currentURL,
@@ -49,17 +52,24 @@ export const EmbedTab = <
         });
       }
     },
-    [editor, block.id, currentURL],
+    [editor, props.blockId, currentURL],
   );
 
   const handleURLClick = useCallback(() => {
-    editor.updateBlock(block.id, {
+    if (!editor.getBlock(props.blockId)) {
+      return;
+    }
+    editor.updateBlock(props.blockId, {
       props: {
         name: filenameFromURL(currentURL),
         url: currentURL,
       } as any,
     });
-  }, [editor, block.id, currentURL]);
+  }, [editor, props.blockId, currentURL]);
+
+  if (!block) {
+    return null;
+  }
 
   return (
     <Components.FilePanel.TabPanel className={"bn-tab-panel"}>
diff --git a/packages/react/src/components/FilePanel/DefaultTabs/UploadTab.tsx b/packages/react/src/components/FilePanel/DefaultTabs/UploadTab.tsx
index fa8a5a2d49..41e726ca72 100644
--- a/packages/react/src/components/FilePanel/DefaultTabs/UploadTab.tsx
+++ b/packages/react/src/components/FilePanel/DefaultTabs/UploadTab.tsx
@@ -29,7 +29,7 @@ export const UploadTab = <
 
   const editor = useBlockNoteEditor<B, I, S>();
 
-  const block = editor.getBlock(props.blockId)!;
+  const block = editor.getBlock(props.blockId);
 
   const [uploadFailed, setUploadFailed] = useState<boolean>(false);
 
@@ -53,6 +53,9 @@ export const UploadTab = <
         if (editor.uploadFile !== undefined) {
           try {
             let updateData = await editor.uploadFile(file, props.blockId);
+            if (!editor.getBlock(props.blockId)) {
+              return;
+            }
             if (typeof updateData === "string") {
               // received a url
               updateData = {
@@ -76,6 +79,10 @@ export const UploadTab = <
     [props.blockId, editor, setLoading],
   );
 
+  if (!block) {
+    return null;
+  }
+
   const spec = editor.schema.blockSpecs[block.type];
   const accept = spec.implementation.meta?.fileBlockAccept?.length
     ? spec.implementation.meta.fileBlockAccept.join(",")
diff --git a/packages/xl-ai/src/api/formats/markdown-blocks/tools/rebaseTool.ts b/packages/xl-ai/src/api/formats/markdown-blocks/tools/rebaseTool.ts
index aff89b423b..2e4b31136f 100644
--- a/packages/xl-ai/src/api/formats/markdown-blocks/tools/rebaseTool.ts
+++ b/packages/xl-ai/src/api/formats/markdown-blocks/tools/rebaseTool.ts
@@ -11,7 +11,11 @@ export function createMDRebaseTool(
   editor: BlockNoteEditor<any, any, any>,
 ) {
   const tr = getApplySuggestionsTr(editor);
-  const md = editor.blocksToMarkdownLossy([getBlock(tr.doc, id)!]);
+  const block = getBlock(tr.doc, id);
+  if (!block) {
+    throw new Error("block not found");
+  }
+  const md = editor.blocksToMarkdownLossy([block]);
   const blocks = editor.tryParseMarkdownToBlocks(md);
 
   const steps = updateToReplaceSteps(